If a circuit has 12 V across a 4 Ω resistor, what is the power dissipated?

Unlock all questions

This demo includes only 20 questions. Upgrade to access hundreds of questions, flashcards, exam simulations, and disable ads.

Full question bankExam simulationsFlashcards
From $24.99Unlock all

Get ready for the NCCER Introduction to Electrical Circuits exam. Study with multiple choice questions, each question comes with hints and explanations. Ace your exam with confidence!

Multiple Choice

If a circuit has 12 V across a 4 Ω resistor, what is the power dissipated?

Explanation:
Power dissipated in a resistor is determined by P = V^2 / R. With 12 V across a 4 Ω resistor, P = 12^2 / 4 = 144 / 4 = 36 W. You can confirm by finding the current first: I = V / R = 12 / 4 = 3 A, then P = VI = 12 × 3 = 36 W, or P = I^2 R = 3^2 × 4 = 36 W. So the resistor dissipates 36 watts.

Power dissipated in a resistor is determined by P = V^2 / R. With 12 V across a 4 Ω resistor, P = 12^2 / 4 = 144 / 4 = 36 W. You can confirm by finding the current first: I = V / R = 12 / 4 = 3 A, then P = VI = 12 × 3 = 36 W, or P = I^2 R = 3^2 × 4 = 36 W. So the resistor dissipates 36 watts.

More Multiple Choice Questions
Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy